How can I composite a product overlay with the correct Kdenlive track when the adjacent lower track is not the source?

Understand the source relationship

A Kdenlive composition combines the clip carrying the composition with another clip. By default, Kdenlive uses the clip in the track immediately below that clip. Track position therefore matters independently of the visual order you intended for the product edit.

For example, an upper product clip might be intended to combine with a background on a lower track, while a packaging graphic sits between them. The adjacent graphic becomes the default source even though the background is the actual target. The result can look like a faulty overlay, an unexpected wipe, or a product image blended with the wrong footage.

The documented Composition track control lists possible tracks below the clip that contains the composition. Choosing another listed track changes which lower clip is used. This is a routing decision: the composition type still determines how the two selected clips interact, while the track selection determines which lower clip is supplied.

Route the intended lower track

First preserve the approved project and work on a copy. Identify the clip that visibly carries the composition bar, then identify the clip you expect to appear beneath or behind it. Record the track positions before changing anything; this prevents a mistaken visual assumption from becoming the new arrangement.

Select the composition and open its composition controls. Locate the Composition track control and compare its current value with the visible result. The default should correspond to the immediately lower track. If the intended product footage, background, or graphic is on another lower track and appears in the available choices, select that track.

Changing this control changes the composition's source track. It does not move clips, change the composition type, or rewrite the underlying product footage. Play the overlap again and inspect a frame where the source has distinctive evidence, such as a package edge, a product label, or a known background detail. Stop when the intended source is selected and that evidence appears consistently through the overlap.

1. Name the composition-bearing clip and its track.
2. Name the intended source and its track.
3. Check whether the intended source is below the composition-bearing clip.
4. Choose that lower track in Composition track.
5. Review a distinctive frame and the full overlap.

Handle an impossible upward route

Kdenlive lists possible composition tracks below the clip carrying the composition. It cannot composite upwards. Consequently, an intended source above the composition-bearing clip will not become available merely because it is visually the desired layer.

When the source is above, reorder the tracks so the source is below the clip with the composition, then reassess the composition track. Track reordering is an editorial recommendation for resolving the documented limitation; the Kdenlive 26.08 manual does not establish a particular drag gesture, shortcut, or menu path for performing it.

After reordering, check whether other planned overlays have changed their relationships. A logo, product cutout, and background may all occupy different tracks, so moving one track can affect more than the immediate composition. Preserve the original arrangement and approve the copy only when the selected source and the rest of the layer relationships still match the edit plan.

Illustrative exercise: isolate the wrong source

Illustrative exercise / 虚构练习: Build a three-track product demonstration with a background on the lowest track, product footage on the middle track, and a logo or packaging overlay on the upper track. Add a composition to the upper clip and observe the default result. Because the default source is the immediately lower track, the product footage is used.

Use distinguishable clips: product footage showing a red zipper on the middle track and a pale wood background on the lowest track. In this fictional arrangement, the upper clip carries the composition. Record that the Composition track control initially refers to the adjacent middle track, while the brief calls for the lower background. Select the background track and review the composition where the lower input should contribute. The control selection establishes the route; do not assume that the zipper disappears everywhere, because the complete output also depends on the chosen composition, opacity and other visible tracks.

For the second branch, place the intended background above the composition-bearing clip. If that track is absent from the Composition track choices, do not keep changing composition types to force it. Reorder the tracks so the background is below, select it if necessary, and review the same distinctive wood-surface frame. Stop when the intended source is listed, the expected evidence is visible, and the full overlapping duration remains correct.

Illustrative Kdenlive track-routing examples and review fields

These are illustrative exercise rows. Save a copy and record your own observations; the example is not an executed acceptance test.

Download review worksheet (CSV)